Related Experiment Videos
Carbonic anhydrase and cardiac pH regulation
J I Vandenberg1, N D Carter, H W Bethell
1Department of Biochemistry, University of Cambridge, United Kingdom.
The American Journal of Physiology
|December 1, 1996
Summary
Membrane-bound carbonic anhydrase (CA) in ferret hearts aids intracellular pH recovery after ischemia. Inhibiting CA slows pH changes, highlighting its crucial role in cardiac tissue.
Area of Science:
- Cardiovascular Physiology
- Biochemistry
- Cellular Biology
Background:
- Membrane-bound carbonic anhydrase (CA) has been identified in mammalian cardiac tissue.
- Understanding the specific location and function of CA in the heart is crucial for cardiac health research.
Purpose of the Study:
- To investigate the histochemical location of CA in the ferret heart.
- To determine the functional role of CA in regulating intracellular pH (pHi) and recovery from ischemia.
Main Methods:
- Histochemical staining (modified Hansson's technique) to locate CA.
- Langendorff-perfused ferret heart model to assess pHi changes using 31P nuclear magnetic resonance spectroscopy.
- Application of membrane-permeable (6-ethoxzolamide) and impermeable (CL-11,366) CA inhibitors.
Main Results:
- CA was localized to capillary endothelial and sarcolemmal membranes in ferret hearts.
- CO2 washout caused a transient rise in pHi, which was significantly reduced by CA inhibitors.
- CA inhibitors slowed the rate of pHi recovery and contractile function after myocardial reperfusion.
Conclusions:
- Carbonic anhydrase facilitates CO2-H2CO3 hydration-dehydration, influencing intracellular and extracellular CO2 concentrations.
- CA enhances CO2 transfer from intracellular to extracellular compartments, significantly aiding pHi recovery post-ischemia.
- Targeting CA may offer therapeutic potential for managing cardiac ischemia and reperfusion injury.